• Question: How many blackholes are in the universe?

    Asked by murphdawg to Niamh, Ned, Laurence, Colin, Aisling on 1 Mar 2016.
    • Photo: Colin Shirran

      Colin Shirran answered on 1 Mar 2016:

      This is a pretty difficult question to answer but I can safely say that we definitely don’t know for sure how many exist. I think an estimate is probably a few hundred million per galaxy, which is less than the amount of stars in a galaxy on average. What is cool though is that pretty much every galaxy in the universe that you can see, including our own, has a supermassive black hole at it’s center, and we all orbit around it. Don’t worry though we aren’t in any danger from it.

    • Photo: Ned Dwyer

      Ned Dwyer answered on 1 Mar 2016:

      Absolutely no idea . But probably loads!

    • Photo: Laurence O'Rourke

      Laurence O'Rourke answered on 3 Mar 2016:

      As Colin said you have a black hole at the centre of each galaxy and there are estimated to be about 100 billion galaxies in the universe, but who’s counting :0)

      There are a few ways to detect them and one of the best ways is through x-rays. We know that black holes are a bit like whirlpools so the closer material gets to the edge, teh faster it goes and the hotter it gets. The temperature can be heated to thousands of degrees which is enough to produce X-rays. Even higher temperatures up to a million degrees produces gamma rays.

      So next time you are getting an x-ray taken of your leg or arm or whatever, remember that black holes are producing them too!!